Self-supporting copper electrode prepared by ultrasonic impact for hydrogen evolution reaction.

Water electrolysis for hydrogen production requires highly active and inexpensive catalysts. Herein, we combine ultrasonic impact nanocrystallization (UIN) technology with nital etching method to rapidly prepare highly efficient self-supporting Cu electrode with abundant low-angle grain boundaries. When used as a catalyst for hydrogen evolution reaction (HER), the as-prepared electrode exhibits an overpotential of 353 mV at a current density of 10 mA cm−2, which is about 200 mV lower than that of the blank Cu plate. Moreover, the overpotential decreased to 246 mV after the stability test of 100 h, indicating a self-optimizing property. This work paves a new way for the preparation of self-supporting electrode with high performance. • Ultrasonic impact nanocrystalline could be used in catalysis. • Cu self-supporting electrode with high density surface dislocation is prepared. • The dislocation density could be precisely adjusted by controlling the etching time. • Electrode exhibits high HER activity and stability, shows self-optimized performance. • Dislocations have lower hydrogen adsorption free energies than perfect crystals. [ABSTRACT FROM AUTHOR]